Re: ShowGraph vs. GraphPlot

*To*: mathgroup at smc.vnet.net*Subject*: [mg109050] Re: ShowGraph vs. GraphPlot*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Mon, 12 Apr 2010 06:51:10 -0400 (EDT)

I think it's primarily a historical issue. The functions for dealing with graphs began in, and mostly still reside in, the standard add-on package Combinatorica. And that's where ShowGraph is. But in recent versions of Mathematica, combinatoric functions have evidently begun a migration into the kernel. In particular, as is typical with the evolving language design, the syntax of functions for different kinds of graphing is being rationalized. GraphPlot, in the kernel, does not require that you first create an object with head Graph (using a Combinatorica function to do so) to feed in as the argument for what is to be plotted. GraphPlot and ShowGraph handle differently such things as labeling edges and vertices, and even choosing where to put the vertices. GraphPlot allows much finer control over the labeling and even the styling of vertices and edges -- often with the expense of complicated options; ShowGraph typically involves less work to produce labeled graphs, but with less control over the results. You might want to take a look at the notebook Graphs.nb that I last revised in 2009 for a course. It covers both ShowGraph and GraphPlot and shows how to convert between the older Combinatorica-type Graph objects and the newer GraphPlot-friendly graph structures, and converting labels for one to the other. See: http://www.math.umass.edu/~murray/Math_455_Eisenberg/Files/files.html On 4/11/2010 4:31 AM, becko wrote: > What's the difference between the functions GraphPlot and > Combinatorica`ShowGraph? > > Why are there two functions for the same task? > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305